Pilgrimmage (Hajj)
Bukhari :: Book 2 :: Volume 26 :: Hadith 712
Narrated 'Aisha:
I was menstruating when I reached Mecca. So, I neither performed Tawaf of the Ka'ba, nor the Tawaf between Safa and Marwa. Then I informed Allah's Apostle about it. He replied, "Perform all the ceremonies of Hajj like the other pilgrims, but do not perform Tawaf of the Ka'ba till you get clean (from your menses)."